Optimal Rasterization for Maskless Lithography

• US 20080224251A1
• Filed: 03/14/2007
• Published: 09/18/2008
• Est. Priority Date: 03/14/2007
• Status: Active Grant

• Current Assignee: ASML Holding NV, ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Holding NV, ASML Netherlands BV (ASML Holding NV)
• Inventors: Zimmerman, Richard Carl, Troost, Kars Zeger, Hintersteiner, Jason Douglas, Chilov, Kamen Hristov, Cuperus, Minne, Van T. Westeinde, Ronnie Florentius
• Granted Patent: US 8,009,269 B2
• Time in Patent Office: Days
• US Class Current: 257/499
• CPC Class Codes: G03F 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
• CPC Class Codes: G03F 7/70358 Scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging
• CPC Class Codes: G03F 7/70475 Stitching, i.e. connecting image fields to produce a device field, the field occupied by a device such as a memory chip, processor chip, CCD, flat panel display
• CPC Class Codes: G03F 7/70508 Data handling in all parts of the microlithographic apparatus, e.g. handling pattern data for addressable masks or data transfer to or from different components within the exposure apparatus
• CPC Class Codes: G03F 7/70791 Large workpieces, e.g. glass substrates for flat panel displays or solar panels

Abstract

A lithographic system is provided in which an extent of overlap between pattern sections is adjusted in order to match a size of a pattern section to a size of a repeating portion of the pattern to be formed.

Claims

1. A lithographic apparatus comprising:

one or more arrays of individually controllable elements configured to modulate a beam of radiation;

a projection system configured to project the modulated beam of radiation onto a substrate; and

a controller configured to control the lithographic apparatus such that the lithographic apparatus exposes a pattern of radiation on the substrate, the pattern comprising a plurality of regions in which a common pattern portion is repeated, and in which the pattern is formed from a plurality of pattern sections, each of the pattern sections corresponding to the modulated beam of radiation,

wherein the controller is configured to control an extent of overlap of the pattern sections, in a first direction, such that a part of the common pattern portion, exposed in two or more regions of the pattern exposed on the substrate, is exposed by a part of the modulated beam of radiation.

2. The apparatus according to claim 1, wherein the controller is configured to control the extent of overlap of the pattern sections in the first direction, such that the extent of the overlap in the first direction is the same for all pairs of adjoining ones of the pattern sections within a region of the pattern.

3. The apparatus according to claim 1, wherein the controller is configured to control the extent of overlap of pattern sections in the first direction, such that the extent of the overlap in the first direction is different for at least one pair of adjoining ones of the pattern sections from that of at least one other pair of adjoining ones of the pattern sections within a region of the pattern.

4. The apparatus according to claim 1, wherein:

the controller is configured to expose the pattern on the substrate by exposing successive stripes of the pattern on the substrate, each of the stripes of pattern being formed from one or more rows of adjoining ones of the pattern sections; and

the one or more rows and the stripes of pattern are parallel to the first direction.

5. The apparatus according to claim 4, further comprising:

an actuator system configured to move the substrate relative to the projection system in a direction parallel to the first direction, while a plurality of the pattern sections are exposed on the substrate during the exposure of one of the stripes of the pattern on the substrate;

wherein the controller is configured to control the extent of overlap of the pattern sections within the stripe of the pattern by adjusting at least one of a relative speed of the substrate and projection system and a timing of exposure of one or more of the pattern sections.

6. The apparatus according to claim 4, wherein the controller is configured to control the extent of overlap of adjoining ones of the stripes of the pattern in a second direction, perpendicular to the first direction, such that a part of the common pattern portion, exposed in two or more regions of the pattern exposed on the substrate in different ones of the stripes of the pattern, is exposed by a part of the modulated beam of radiation.

7. The apparatus according to claim 6, wherein the controller is configured to control the extent of overlap of adjoining ones of the stripes of the pattern in the second direction, such that the extent of the overlap in the second direction is the same for all pairs of adjoining ones of the stripes of the pattern within a region of the pattern.

8. The apparatus according to claim 6, wherein the controller is configured to control the extent of overlap of adjoining ones of the stripes of pattern in the second direction, such that the extent of the overlap in the second direction is different for at least one pair of adjoining ones of the stripes of the pattern from that of at least one other pair of adjoining ones of the stripes of the pattern within a region of the pattern.

9. The apparatus according to claim 4, wherein the controller is configured to control a width of one or more of the stripes of the pattern in a second direction, perpendicular to the first direction, such that a part of the common pattern portion, exposed in two or more regions of the pattern exposed on the substrate in different ones of the stripes of the pattern, is exposed by a part of the modulated beam of radiation modulated by a same part of the one or more arrays of individually controllable elements.

10. The apparatus according to claim 9, wherein the controller is configured to control the width, in the second direction, of the stripes of the pattern, such that the width in the second direction is substantially equal for all the stripes of the pattern within a region of the pattern.

11. The apparatus according to claim 9, wherein the controller is configured to control the width, in the second direction, of the stripes of the pattern, such that the width in the second direction is different for at least one of the stripes of the pattern from that of at least one other one of the stripes of the pattern within a region of the pattern.

12. The apparatus according to claim 9, wherein the controller is configured to control the width of the stripe of the pattern in the second direction by setting, as required, at least a part of at least one of the one or more arrays of individually controllable elements, such that radiation is not exposed on the substrate by a corresponding portion of the modulated beam of radiation.

13. The apparatus according to claim 9, further comprising:

a movable barrier configured to prevent (a) a controlled proportion of the cross-section of the modulated beam of radiation from being projected onto the substrate or (b) a controlled proportion of the cross-section of at least one of the one or more arrays of individually controllable elements from being illuminated by the beam of radiation;

wherein the controller is configured to control the width of the stripe of the pattern in the second direction by controlling a position of the movable barrier.

14. The apparatus according to claim 1, wherein:

the pattern exposed on the substrate comprises a second plurality of regions in which a second common pattern portion is repeated; and

the controller is configured to control extent of overlap, in the first direction, of pattern sections corresponding to the second plurality of regions independently of the control of the extent of overlap of pattern sections corresponding to the first plurality of regions, such that a part of the second common pattern portion, exposed in two or more regions of the pattern exposed on the substrate, is exposed by a part of the modulated beam of radiation modulated by a same part of one of the one or more arrays of individually controllable elements.

15. The apparatus according to claim 1, wherein each region of the pattern corresponds to a portion of the substrate on which a discrete device is to be formed.

16. The apparatus according to claim 1, further comprising:

a data processor configured to convert pattern data, corresponding to the common pattern portion, into corresponding control signals for the one or more arrays of individually controllable elements; and

a memory configured to store the control signals,

wherein the same control signals, stored in the memory, are provided to the one or more arrays of individually controllable elements in order to expose the common pattern portion in a plurality of the regions on the substrate.

17. The apparatus according to claim 16, wherein the repeated common pattern portions are separated by non-repeating pattern portions.

18. The apparatus according to claim 17, further comprising:

a second data processor configured to convert pattern data, corresponding to the non-repeating pattern portions, into corresponding control signals for the one or more arrays of individually controllable elements.

19. A device manufacturing method, comprising:

modulating a beam of radiation using one or more arrays of individually controllable elements;

projecting the modulated beam of radiation onto the substrate;

forming the modulated beam of radiation with a pattern having a plurality of regions, in which a common pattern portion is repeated;

forming the pattern from pattern sections, each of the pattern sections corresponding to a section of the modulated beam of radiation; and

controlling an extent of overlap of the pattern sections, in a first direction, such that a part of the common pattern portion, exposed in two or more regions of the pattern exposed on the substrate, is exposed by a part of the modulated beam of radiation by a same part of the one or more arrays of individually controllable elements.

20. An integrated circuit device manufactured according to the method of claim 19.

21. A flat panel display manufactured according to the method of claim 19.